The embodiment relates to a configuration of a communication terminal, and more particularly, to an antenna apparatus and a feeding structure thereof.
Generally, a communication terminal includes an antenna apparatus to transmit/receive an electromagnetic wave. The antenna apparatus resonates at a specific frequency band to transmit/receive an electromagnetic wave having a corresponding frequency band. In this case, when the antenna apparatus resonates at the corresponding frequency band, impedance has an imaginary number. Further, an S parameter of the antenna apparatus is rapidly reduced at the corresponding frequency band.
To this end, the antenna apparatus includes a conducting wire having an electric length of λ/2 with respect to a wavelength λ corresponding to the desired resonance frequency band. The antenna apparatus transmits the electromagnetic wave through the conducting wire and the electromagnetic wave forms a standing wave in the conducting wire so that resonance is achieved in the antenna apparatus. In this case, the antenna apparatus may include a plurality of conductive waves having mutually different lengths to expand a resonance frequency band.
However, the operation efficiency of the antenna apparatus may be deteriorated. Since the electric length of the conducting wire in the above-described antenna apparatus is determined corresponding to a resonance frequency band, the size of the antenna apparatus is determined depending on the resonance frequency band. Thus, it is difficult to improve the operation efficiency of the antenna apparatus without enlarging the size of the antenna apparatus.